hi,
you would need to solder the jtag cable to your board in order for it to access the nand chip and to flash it.
to be honest it sounded cool so i got the cable before i looked into it and just dont have the time to figure it out, but there are plenty of tutorials on the web.

Little bit more than that. The console must have an old dashboard otherwise the hack doesnt work. Majority of people will have updated either by playing games with the title update or downloading the dashboard update when connecting to live.